Humidification Done Right

Fundamentals and Applications

Presenters

Nicholas Lea, P. Eng, LEED AP BD+C

Matt Nowak

Eric Brodsky, PE

Global Product ManagerNortec Humidity Ltd.

North American Sales ManagerArmstrong International

Director of TechnologyResearch Products Inc.

Agenda

1. Fundamentals of Humidity• Key Terms and Definitions

• Humidification Applications

2. Humidification: Commercial and Industrial• Steam Solutions

• Liquid Water Solutions

3. Humidification: In the Home• Residential Applications

• Technology Solutions

4. Questions

What is Humidity and How Do We Measure It?

Humidity

• The amount of water vapor in the air

• Measured in “Absolute” or “Relative” terms

Absolute Humidity

• Mass of water in particular volume of air

• Expressed as mass (grains/lbda or gw/kgda)

Relative Humidity

• Amount of water vapor in the air relative to how much it can hold at a given temperature (%)

How Much Water Can the Air Hold?

It depends on the temperature of air!

1 lb (kg) of Air35°F (2°C)30 gr (2g/kg)

100% RH

1 lb (kg) of Air72°F (22°C)30 gr (2g/kg)

25% RH

Sensible Heating

How Much Water Can the Air Hold?

35°F

(2°C)72°F

(22°C)120°F

(49°C)

Temperature

100% RH

25% RH

Absolute Humidity

30 gr (2g/kg)

120 gr (8g/kg)

The Psychrometric Chart

Effect of Outdoor Conditions

Heating Climates

• High outdoor RH does not translate indoors!

RH % Indoor RH% When Heated to 70°F

100 2 4 5 6 7 9 12 17 19 23 29 36 42 53

60 1 2 3 3 4 5 7 9 11 14 17 21 26 31

50 1 1 3 3 4 4 6 8 9 12 14 18 22 2645 1 1 2 3 3 4 6 7 8 11 13 16 20 24

40 1 1 2 3 3 4 5 7 7 10 12 14 18 21

35 1 1 2 2 2 4 5 6 6 7 10 12 15 18

30 0 1 2 1 2 3 4 5 5 7 9 11 13 15

25 0 1 1 1 2 3 4 4 4 5 7 9 11 13

20 0 1 1 1 2 2 3 3 3 5 5 7 9 10

-20 -10 -5 0 5 10 15 20 25 30 35 40 45 50

Outdoor Temperature (°F)

How Much Humidity is Enough?

Humidity Control Is Needed Everywhere• Warm Climates: Dehumidification to remove excess moisture

• Cool Climates: Humidification to prevent excessive dryness

Humidification for People• Important for health and well being of occupants

• Applications at work and home

Humidification for Industry and Process• Moisture sensitive materials

• Product Quality / Process Reliability

Human Body Response• Human body is ~60% water• Body doesn’t sense moisture well

Humidity and Respiratory Infections• Evidence of link between moisture and cold / flu

transmission

• Clinical trials between 1963 and 1985 showed significant reduction of respiratory infects when mid-range humidity was maintained [1-5]

• 2013 NIOSH/CDC Research showed reduced infectivity of flu virus aerosols with mid-range air humidity levels [6]

Humidification for People

Photo Credit: iStock 000018649460

1. Ritzel G, Sozialmedizinische Erhebung zur Pathogenese und Prophylaxe von Erkältungskrankheiten, sog. «Kindergartenstudie» Zeitschrift für Präventivmedizin 1966, 11. 9-162. Sale C, Humidification to Reduce Respiratory Illnesses in Nursery School Children, Southern Medical Journal, July 1972, Vol 653. Green G H, Winter humidity and related absenteeism in Canadian hospitals, Digest of the 3rd. CMBES4. Green G H, The effect of indoor relative humidity on absenteeism and colds in schools, ASHRAE Trans., Vol. 80, Part II5. Gelperin A, Humidification and upper respiratory infection incidence, Heating, Piping and Air Conditioning, 45:3, 19736. Noti JD et. al, High Humidity Leads to Loss of Infections Influenza Virus from Simulated Coughs, PLoS ONE 8(2): e57485, 2013

Humidity and Productivity

• Study in Germany found possible influence of air humidity on eye irritations, dryness of mucous membranes, and vocal stress.

• Survey responses showed that insufficient air humidity have negatively impact well-being, motivation, and performance. [1]

Humidification for People

1. Rief S and Juric M, Air Humidity in the Office Workplace, Fraunhofer IAO, 2014

ASHRAE Standard 55

“There are no established lower level humidity limits for thermal comfort, consequently, this standard does not specify a minimum humidity level.

NOTE: Non-thermal comfort factors such as shin drying, irritation of mucus membranes, dryness of the eyes, and static electricity generation may place limits of the acceptability of very low humidity environments.”

Photo Credit: DRAABE Industrietechnik GmbH

©2014 Fraunhofer IAO

The Sterling Chart

• Common design reference

• Suggests mid-range 30 - 60% is optimal

• ASHRAE RP-1630 is working to update chart with latest research

Humidification for People

©ASHRAE, www.ashrae.org. 2012 ASHRAE Handbook: HVAC Systems & Equipment, Ch 22.1Adapted from Sterling et al. 1985

http://www.ashrae.org/

Humidity and Process

Humidity Affects Materials• Swell and shrink effects

• Paper, wood, textiles, concrete

Humidity Affects Static Charge Accumulation• Dry air resists charge dissipation

• High charge voltages result in spark discharge

Humidity Affects Production Processes and Product Storage• Painting, concrete curing, leather processing all rely on moisture balance

• Food storage and processing; fruit, vegetables, cheese

Photo Credit: iStock 000015139309

Electronics [1]

50 - 55% @ 71°F (21°C)

[1] 2015 ASHRAE Handbook: HVAC Applications, Chapter 14

Textiles [2]

50-70%

[2] 2015 ASHRAE Handbook: HVAC Applications, Chapter 21.2, Figure 1Photo Credit: iStock 000022275438

Printing [3]

43 – 47% RH ±2%

3. 2015 ASHRAE Handbook: HVAC Applications, Chapter 20.3, Figure 1Photo Credit: iStock 000046996430

Humidity Design Resources: More Information

ASHRAE Handbooks• 2016 Systems and Equipment Chapter 22

• 2015 HVAC Applications

AHRI Humidifiers Section• www.ahrinet.org

• Click Contractors and Specifiers

©ASHRAE, www.ashrae.org

©AHRI, www.ahrinet.org

Local Standards and Norms• Codes, Federal Standards, etc.

• Euro Standard EN 15251:2007

Photo Credit: N. Lea

http://www.ashrae.org/http://www.ashrae.org/

Fundamentals of Humidity: Summary

Humidity• Relative to temperature

• High outdoor RH does not equal acceptable indoor RH

Humidity for People• Evidence shows link between humidity and health

• Indoor RH 30 – 60%

Humidity for Process• Many processes are moisture dependent

• Drying rates, dimensional stability, static, strength

Industrial / CommercialHumidifiers and Selection – Done

Right

Methods of Humidification

Direct Steam Injection

Heated Pan (Atmospheric)

Adiabatic

0 10 20 30 40 50 60 70 80 90

10

20

30

40

50

90 80 70 60 50 40 30PSYCHROMETRICS

%RH

20

30

40

50-ISOTHERMAL HUMIDIFICATION

ISOTHERMAL

HUMIDIFICATION

-ADIABATIC HUMIDIFICATION

ADIABATIC

HUMIDIFICATION

Isothermal vs. Adiabatic Energy Usage

HumidificationProcess

AdiabaticIsothermal

Phase Change /Latent Heat

Heating Water to212 F

Water IncomingState

Evaporation / PhaseChange

Atomization

Water Incoming State

Air Pre-Heat / Sensible Heat Gain

Humidifier Selection

Isothermalvs.

Adiabatic

Is Steam Available?

What utilities are available?

What type of water is going to be

used?

What space is available

for the humidifier?

What type of accuracy is required?

Information for Load (Capacity) Required

Where is the Humidity going to be added to the air?

– Duct / AHU

• Tunnel size (H x W x L)

• Airflow

• Temp of Air at this point

• Amount of Outside Air / Conditions of that air

– Room

• Dimensions of Space

• Air Changes per Hour (# of Doors and Windows)

What conditions are you trying to achieve?

Direct Steam Injection

©ASHRAE, www.ashrae.org. 2012 ASHRAE Handbook-HVAC Systems & Equipment, Ch 22, Page 8

http://www.ashrae.org/

Direct Steam Advantages

Reliable performance

Available in a wide range

of capacities

Low maintenance requirements

High Turndown /

Great Control

Small Footprint

Heated Pan (Atmospheric)

©ASHRAE, www.ashrae.org. 2012 ASHRAE Handbook-HVAC Systems & Equipment, Ch 22, Page 8

http://www.ashrae.org/

Heated Pan Advantages

• Compact size

• Good Control / Turndown

• Self-diagnostics

Electric Units

• Low Energy Cost

• Higher Capacities

• Self-diagnosticsGas Units

• Available in a wide range of sizes and high output capabilities

• Reliable operation

Steam to Steam Units

Adiabatic Humidifiers

Adiabatic Humidifier Advantages

Provides potential

energy benefit of Evaporative

Cooling

High turndown of output

Wide range of capacities

Modulation of output / Tight

control

Humidity Control

Controllers

Humidistat

Sensors

BAS / Communication

Protocol

Safeties

High Limit Humidistat

Pressure Switch (Airflow sensor)

Temperature Switch (if

applicable)

Optional Accessories

Modulating High Limit

Outdoor Temperature

Reset

Who to consult?

ResidentialHumidifiers and Selection – Done

Right

Residential - Humidification Done Right

HealthComfort

Energy SavingsPreservation

Relative Humidity – Dry Air

Dry outdoor air !

The house gets very Dry !Enters the house!

Today it is common to encounter:

• Small equipment rooms, tight workspaces…

• Equipment and plenum size limitations…

• Various air volumes with various run times…

• Heat pumps with lower plenum temperatures

• Hydronic or radiant heating equipment

• Modulating furnaces

• Tight construction

• Various ventilation rates

Changing Building Envelopes and HVAC Equipment

Key Humidifier Application Criteria

HVAC Equipment:

• Type of HVAC equipment

• HVAC equipment physical size

• Location of HVAC equipment

• Plenum temperatures

• Airflow distribution and zoning

• HVAC controls

Key Application Criteria

Humidification Load:

• House size

• Physical Characteristics

• Occupants

• Geographic Location

Water characteristics :

• Hard, soft or softened

• Hot or cold

• Conductivity

• City or well/septic

• Atomizing

• Evaporative– Fan-Powered

– Bypass

• Steam– Resistive

– Electrode

Residential Humidity Solutions

Atomizing Humidifiers

AdvantagesInstall on Heat/Cool Systems

Install on Heat Pump Systems

Works with demineralized water

Adiabatic

Evaporative Humidifiers

Advantages

Install on Heat/Cool Systems Install on Heat Pump Systems

Adiabatic

Many sizes and capacities

Low water usage models

Use hot water for higher capacity

Powered or bypass humidifiers

Various control options

Advantages Install with any HVAC systems:

Radiant or Hydronic Heating

Heat/Cool Systems

Heat Pump Systems

Ducted Systems

Used in:

All type of Climates

Small Equipment Closets

Stand Alone Operation

Modulating Controls

High Capacity Needs

Steam Humidifiers

Resistive and Electrode Humidifiers

Control Strategies

Manual control

Automatic Controls

Modulating Controls

IAQ Thermostats

AHRI Guideline AHRI Guideline for Residential Humidifier Humidification Load;

equipment selection; installation practices; and servicing practices.

In summary

Residential humidification is needed.

Select proper humidifier based on:

– Building construction

– HVAC equipment

– Humidification systems

– Controls

– Customer expectations

Questions